WASHINGTON -- The White House on Tuesday ruled out imposing any form of a coronavirus vaccine passport in the United States, but said private businesses were free to explore the idea.

"The government is not now, nor will be, supporting a system that requires Americans to carry a credential. There will be no federal vaccinations database and no federal mandate requiring everyone to obtain a single vaccination credential," Press Secretary Jen Psaki told reporters.

So-called vaccine passports, showing that someone has been inoculated against COVID-19, have been touted around the world as a potentially powerful tool in safely reopening countries to mass gatherings and travel.

However, the idea has prompted widespread pushback over concerns due to potential privacy or other civil rights abuses.

Psaki said that the strongest interest comes from private businesses looking to reopen sites where "there are large swaths of people," like in stadiums or theaters.

She said the government will be issuing "guidance" with "important answers to questions that Americans have in particular around concerns about privacy, security or discrimination."

"Our interest is very simple from the federal government, which is Americans' privacy and rights should be protected, and so that these systems are not used against people unfairly," Psaki said.